The field of the invention relates generally to graphical user interfaces. More particularly, the field of the invention relates to a method for dynamically magnifying a moveable selected region of a digital image while preserving the visual context of the image.
When viewing images displayed on a computer or television screen, one often experiences difficulty discerning small details and would like to view a portion of the image in a magnified format. Conventional methods for digital image magnification solve this problem by replacing the original unmagnified image with a magnified image of a selected region of the original image. Although this provides a magnified format for viewing small details of the original image, it has the disadvantage that the context of the magnified image presented to the viewer is lost.
For example, FIG. 1 shows an original unmagnified image as it is displayed on a typical computer or television screen. After selecting a region 100 of the image, conventional magnification methods fill the entire screen with a magnified image of the selected region, as shown in FIG. 2. The magnified image displayed in FIG. 2, however, does not provide any context for the magnified region. Without contextual cues, the viewer can lose track of the meaning of the magnified image. Also, the image can be confused with other portions of the original unmagnified image. For instance, house 102 in FIG. 2 may be confused with house 104 in FIG. 1 since the houses are distinguishable only by their context. Some methods for magnification allow dynamic movement of the selected region 100 that is magnified. A pointing device is used to control the position of the magnified region while the magnified image is being viewed. Using this technique, however, one must determine the context of the magnified image by moving the selected region in various directions to bring the contextual information into view. This approach is both slow and inconvenient.
In view of the above problems present in conventional methods of image magnification, there is a need to provide an image magnification method that magnifies a selected region of an image while simultaneously preserving the continuity and integrity of the original unmagnified image that forms the visual context of the magnified region. There is also a need to provide a method of image magnification that permits dynamic control of the position of the magnified region and the degree of magnification. Other objectives and advantages will be apparent from the following description and drawings.
In order to achieve the foregoing objectives and advantages, an aspect of the present invention provides a method for magnifying a selected region of an image while preserving the visual context of the region. A selected region of a digital image is magnified and displayed in a floating plane region superimposed on the original image. The floating plane region is also termed a magnifier since the image data in the floating plane may be selectively magnified to provide a greatly enlarged image of the selected region while preserving the visual context of the image outside the parameters of the magnifier. Because the floating plane area is smaller than the original image area, the context of the magnified region remains displayed around the magnified image. The area of the floating plane region is equal to a magnification factor times the area of the selected region. In another aspect of the invention, the selected region may be moved, e.g., in response to the movement of a user-controlled pointing device. As the selected region moves across the original image, the magnified image displayed in the floating plane region is dynamically modified.
In one implementation of the invention, the floating plane region is superimposed above the selected region so that the floating plane moves as the selected region moves. The effect is similar to that of a magnifying glass moving in a plane above the image. As the floating plane is moved, an aspect of the invention provides for restoring a portion of the original image which was previously covered by the floating plane. The visual context of the image is therefore preserved while enabling a movable portion of the image to be magnified.
It will be appreciated that preserving visual context is especially advantageous when magnifying a line of text or other image data whose interpretation is context dependent.
According to an aspect of the invention, the magnified image in the floating plane region can be superimposed on a moving image to provide a moving magnified image while preserving the visual context of the moving image on the computer screen.